modification to form_prep() solution.  A bandaid really, to return the $str if the field has already been prepped
diff --git a/system/helpers/form_helper.php b/system/helpers/form_helper.php
index 4c229ae..c5e977a 100644
--- a/system/helpers/form_helper.php
+++ b/system/helpers/form_helper.php
@@ -613,9 +613,13 @@
 			return '';
 		}
 
+		// we've already prepped a field with this name
+		// @todo need to figure out a way to namespace this so
+		// that we know the *exact* field and not just one with
+		// the same name
 		if (isset($prepped_fields[$field_name]))
 		{
-			return $prepped_fields[$field_name];
+			return $str;
 		}
 		
 		$str = htmlspecialchars($str);